Hawks are among the smartest predators with excellent vision and hearing.
Seemingly, hawks circle to scan for their prey.
However, it’s mainly because they utilize thermals or rising air currents to soar in the higher altitudes and so, they circle to stay afloat within these thermals.
You must be wondering what are thermals?
Let’s find out..
What are Thermals?
Simply put, thermals are warm air updrafts.
You see, the earth’s surface is not uniform and so, the sunlight heats it unevenly.
Consequently, the air heats up far more at places compared to their surroundings.
This lowers the air pressure, and the heated air starts to rise, thereby, forming warm air currents or “thermals”.
Since, heat from sunlight forms thermals, therefore, they are present only during the day.
That explains why hawks fly mostly during the day.
I guess now you must be wondering
Why do hawks use thermals?
Why do Hawks Use Thermals?
If “work smart, not hard” was about birds, then Hawks would have been the poster birds for it.
You see, hawks are relatively large birds.
They can fly by flapping but that will consume a lot of energy exhausting the bird.
A tired hawk may not even be agile enough to capture a snail.
Therefore, raptors like hawks, have adapted to exploit thermals.
Their thick broad feathers allow them to maneuver through the wind, or more appropriately wield it.
Thermals assist a hawk to reach unprecedented heights while conserving its energy for efficient hunting.
Though, that still doesn’t explain why hawks fly in circles, while others like sparrows don’t.
What Does it Mean When Hawks are Circling?
Though circling over and over a single place does not seem wise.
However, it allows a hawk to completely survey an area for signs of both game and possible threats.
That said, all raptors circle to increase their productivity.
If they didn’t, you might find more raptors dead than any of their victims.
For instance, a vulture can easily locate a carcass, but if he is unable to detect hidden predators, he won’t survive much longer.
For hawks, circling can either mean they are searching for food or looking for mates.
But if they are lingering in your community where they have never been observed before, then chances are your neighborhood is housing either some favorite food delicacies or confusing elements like mirrors.
But if thermals help in flying then:
Why Do Small Birds Flutter and Not Circle?
It’s because, for a small bird, flapping wings is not only easier but also safer than flying via thermals.
Well, a small bird has wings developed for vigorous flapping.
Also, they are relatively lightweight, therefore, they can easily lift themselves.
So, flapping does not cost as much of a small bird’s energy compared to a large bird.
Besides, a small bird is highly likely to become prey. Thus, the safest place for such a bird is close to the earth’s surface where it can find some cover to evade predators.
Since circling within thermals involves roaming onto high altitudes, therefore, gliding through thermals may only make a small bird more vulnerable.
Of course, nothing beats surviving one more day in the wild, even if it means fluttering forcefully.
Indeed, safety is one of the core reasons why birds form flocks.
Yet, raptors are the slayers, so they mostly fly and hunt solo.
But if hawks hunt alone,
One may question..
Why do Hawks Circle in Groups?
Do you know what’s the easiest way to spot a thermal?
Find another bird circling within one!
Therefore, when there is one hawk circling, another one joins in, and then more follow.
So, it seems like hawks are circling in groups when they are just flying solo.
Since these hawks are flying through the same thermal currents, consequently, their movements appear synced like some sort of circular ballet.
Interestingly, a group of hawks is termed “kettle” precisely because their activities look coordinated, resembling water boiling in a kettle.
Ordinarily, not many hawks circle together.
It is such a magnificent sight where hawks circle in rhythm and none of them sabotages another, while they are only a few feet apart.
Now, you may be wondering,
What Are The Ideal Places To Observe Hawks Circling?
Places, where hawks need to cram onto a single series of thermals, are the best spots to observe hawks circling. These include:
- Narrow Paths like mountain passes or canyons.
- Paths between two large water bodies.
- Shorelines where birds halt and gather, before flying further.
However, I suggest that you call your local bird association office to find such a place.
They will recommend certain buildings, watchtowers, or mountain tops.
You can even become a volunteer for counting and identifying birds within migrating kettles.
That said, all raptors and most migratory birds manipulate thermals to some extent.
Thermals also explain why birds choose certain routes for immigration.
This, therefore, explains why certain species of birds do not migrate any longer.
Though, this justifies why hawks circle but,
If kettles are not truly flocks, why would a hawk talk? Or say,
Why Do Hawks Circle and Screech?
A typical hawk screeches while circling to either mark its territory or attract a mate.
Now, the pitch of screeching depends on a hawk’s gender and age.
A male hawk is about two-thirds the size of a female.
The small size contributes to a hawk’s agility as well as its shrill voice.
So, a male with a more piercing sound is considered a dominant male.
And so, male hawks screech a certain “chwirk” sound while courting to declare their territory.
Though, female hawks and their nestlings, screech only to call the male hawk for food during the nesting period.
That aside, fledglings only rarely screech, even if they do it’s a weak hoarse scream.
But, if it’s not the breeding season, a hawk may screech only to warn off other predators from its territory.
Do Hawks Screech While Hunting?
A hawk likes the element of surprise and screeching while hunting will only alert the prey which may then hide.
Besides screeching during a chase is way too dramatic for a silent predator such as a hawk.
It’s like declaring out loud “I am hunting, you flee before I catch you”.
And so, it’s completely against a hawk’s signature move of jump diving and taking the prey before it even finds out that it’s been taken.
An exception to all this is Harris’ Hawk.
These hawks live and hunt as flocks or say, “True Kettles”.
Of course, they communicate with screeching while hunting.
Now you may be interested in:
Will a Hawk Attack a Human?
Well, Hawks are extremely rational, and they know they cannot take on a human.
Normally, a hawk would not even dare to attack a human.
So, if you are trying to reach a hawk’s nest, they may jump dive on you to scare you off and may go as far as hitting your face with their talons or beaks.
I reckon you would be fine if you don’t bother baby hawks.
Unless you have cute small pets.
Now, a hawk wouldn’t try to eat anything bigger than a squirrel.
That means all your bird family members, are just tasty treats, even your macaws.
Cats and dogs are relatively safe from hawks.
But I wouldn’t say that about their pups or cubs.
Adult dogs like chihuahua can also become prey to hawks.
That said, I wouldn’t leave a toddler alone if there are kettles of hawks circling nearby.
Check out these related articles about hawks you may be interested in
Hawks use thermals or warm air updrafts to soar on high altitudes and they circle just to stay within the bounds of a thermal.
A hawk screeches while circling to show its dominance and to attract mates.
Normally, a hawk wouldn’t attack a human unless they perceive him as a threat.
Even so, human pets often fall prey to hawks.